Crucible furnace



Ami l 192%.

F. M. ILER CRUCIBLE' FURNACE Filed Dec. 1 1924 2 Sheets-Sheet 1 April 13 1926. 1,589,733

F. M. ILER CRUCIBLE FURNACE Filed Dec. 1. 1924 2 Sheets-Sheet 2 FRANKLIN ILIEB, 013 CLEVELAND, OHIO.

CRUCIBLE FURNACE.

Application filed December '1 0 all whom it may concern:

Be it known that l, FRANKLIN M. limit, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Crucible Furnaces, of which the following is a full, clear, and. exact description.

This invention relates to crucible furnaces of the type in which heat is applied to a crucible supported Within the furnace and in which the furnace is formed of separable sections permitting access to the interior thereof for inserting and removing the crucibles.

One of the principal objects of the present invention is to provide a sectional furnace of such construction that the insertion and removal of the crucibles is facilitated.

A further object is to provide a construction in which the movable section of the furnace is mounted for vertical swinging movement and in which means is provided for counter-balancing the movable section to facilitate the lifting thereof.

A further object is to provide releasable means for retaining the vertically swinging section in elevated position while a crucible is being removed from the furnace.

With the above and other objects in view, the invention maybe said to comprise the furnace construction as illustrated in the accompanying drawings hereinafter described and particularly set forth in the appended claims, together with such variations and modifications thereof as will be apparent to one skilled in the art to which the invention appertains.

Reference should be had to the accein panying drawings forming a part of this specification in which l is an axial vertical section through the furnace; Fig. .2 is a plan view of the lower fixed s ction of the furnace; Fig. 3 is a plan View of the furnace with the upper section and cover in operative position; Fig. 4 is a side elevation showing the furnace opened for removal of the crucible; Fig. 5 is a detailed view showing the shiftable pawl controlling counterweight in side elevation; Fig. 6 is a sectional detail view of the cover pivot showing the inclination of the pivot for causing the cover to be lifted off its seat during opening move i'riiht Fif 'l .ilee

I a refractory 1, 1924. Serial No. 753,105.

the furnace consists of a lined lower section upon which the crucible issupported, a vertically swinging upper section 2 and a latorally swinging cover 3, the upper section 2 being connected to the lower section by a horizontal pivot 4i sov that it can be swung vertically with respect to the lower section and the cover 8 being secured to the top of the upper section 2 by means of a vertical pivot 5 which is above the pivot e, the pivot 5 permitting the cover to be swung to a position at the rear of the section 2 and of the pivot 4 so that-a considerable portion of the weight of the section 2 is counterbalanced permitting the section 2 to be easily lifted to an elevated position such as shown in Fig. 4 S0 that a crucible 6 may be easily lifted out through the open front of the furnace.

The lower section 1 of the furnace is pro vided with a hollow bottom formed by an outer bottom plate 7 and an inner bottom plate 8 which are spaced apart to form an air space 9 at the bottom of thefurnace. The lower section 1 also has a hollow tubular wall formed by an outer cylindrical wall 10 preferably formed of inner and outer metal sheets with a sheet of insulating material between them which is secured to'the outer base member 7 and an inner cylindrical wall 11 which is secured to the inner base member 8, the walls 10 and 11 forming an annular airspace 12 between them which is in communication with the space 9 at the bottom of the furnace.

The upper edge of the tubular-wall of the section 1 slopes downwardly from one. side of the furnace to the other and the upper end of the annular air space 12 is closed by an elliptical reenforcing ring 13 which secured to the upper edges of the walls 10 and 11. The lower section 1 is provided with a refractory lining Mythc crucible 6 being supported within the lower section upon a supporting steel 16 in the form of block resting upon the bottom of the lining 14.

The furnace is heated by means of a tangentially disposed burner nozzle 17 which projects through the w ll of thesectiolfi 1 adjacent to the b t thereof. fuel being i ly-= l 1 n ply pipe 18 leading from a suitable supply of fluid fuel. The nozzle 17 is surrounded by an air inlet tube 19, the'outer end of which communicates with the interior of a casing 20 secured upon the wall of the furnace. The interior of the casing 20 communicates with the annular air spacelz? in the cylindrical wall of the furnace through an opening 21 which-is controlled'by a suitable manually operated valve 22, air being supplied to the burner through theinterior of the hollow *alls of the section 1 so that the air is preheated before it delivered to the burner nozzle, air being supplied to the air spaces 9 and 10 through an air inlet conduit 23 which may lead from a suitable air compressor.

The bottom of the furnace is preferably so constructed that any fluid fuel which might be discharged into the interior of the furnace will be drained through the bottom without being permitted to enter the air preheating chamber. To this end the outer bottom plate 7 is provided with a series of openings 24 which are surrounded by upwardly projecting flanges 25 and the inner bottom member 8 is provided with open ings 26 which register with the openings 24, the openings 26 being surrounded by downwardly extending flanges 27 which fit within the flanges 25'of the bottom member 7, the flanges 25 serving to support the inner bottom member 8 and to space the same from the outer bottom member 7. In case the interior of the furnace should become flooded with liquid fuel, the liquid will drain through the porous refractory lining and flow through the inlet openings 26 and 2-i so that there is no danger of an explosive mixture being formed within the preheating chamber.

The upper section 2 of the furnace has a cylindrical metallic outer shell 28 which has its lower edge cut on an incline to correspond to the upper edge of the lower section 1 and reenforced by an elliptical ring 29 which rests upon the r-eenforcing ring 13 of the lower section during operation of the furnace. At the upper edge thereof the outer shell 28 of the upper section is provided with areenforcing ring 30 which has an in wardly extending flange 31 which extends inwardly from the upper edge of the shell 28. The upper section 2 has a cylindrical refractory lining 32.

Means are provided for n'iaking the connection between the upper and lower sections of the furnace fluid tight and to this end the elliptical reenforcing ring 13 of the lower section has a rib S l projecting upwardly from its top face which is adapted to enter a groove 35 in the underface of the rcenforcing ring 29 at the bottom of the upper sec tion 2. The groove has f1 ted therein an asbestos packing ring 36 and in order to provide a more effective seal the upper edge of the rib tapered or rounded sothat the rib has a wedging engagcn-ient with the packing ring 36 preventing escape of gr. through the joint between the two sections of the furnace.

To provide for the pivotal mounting of the upper section 2, the elliptical recnloro ing riiigltl adjacent the highest point of the wall of the lower section is provided with a pair of outwardly extending lugs 37 and the lower reenforoing ring 29 of the upper section 2 is provided with a pair of outwardy projecting lugs 38 which fit between the lugs 37 of the lower section and are con nected thereto by the horizontal pivot pin 4!.

The co er 3 consists of a cast iron ring 39 which has a flat base portion provided with an inwardly projecting flange 4-0 and resting upon the top surface of the reenforcing ring 30 at the upper edge of the upper section 2 of the furnace. The inwardly pr jecting flange 40 of the ring supports a circular fire clay block ll whicn extends over the open top of the furnace and is provided with a. central opening thrmigh which the burned gases may escape. The ring 30 at the top of the upper section 2 is provided with an outwardly extending lug 43 above the pivot 4 and the ring of the cover is provided with a corresponding lug l i which rests upon the top of the lug 43, the cover being pivoted upon the section 2 by means of a pivot pin 5 fixed at its lower end in the lug and projecting through an opening in the lug il-5i.

The pivot pin 5 is inclined laterally at a very slight angle with respect to the vertical and the opening in the lug if of the cover in which the lug fits is so inclined that the cover when in closed position seats properly on the ring 30. The inclined pivot permits the cover to turn in one direction only and causes the cover to be lifted out of contact with the ring 30 during the first part of the opening movement so that the cover does not drag over the ring 30 in opening and n'ioveinent of the cover past closed position in closing is prevci'itcd. it a point diametrically opposite the pivot 5 the ring- 39 of the cover is provided with an integral bar receiving socket t?) and diametrically opposite the pivot l the lower ring 25) of the upper section 2 is provided with an intcgral bar receiving socket 46. When it desired to open the furnace for removal or insertion of the crucible, a bar is inscrtml in the socket and the cover 3 is turned laterally about the pivot 5 through i to position the cover rcarwardly of the pivot 4- and the bar is then inserted in the soclre' to lift the upper section 2 which is countcrbalanced by the cover 3 to the elevated no sition shown in Fig. 4 to permit a crucible to be lifted out through the front of the furnace or to permit a crucible to be inserted through the front of the furnace into position upon the stool 20. It should be noted that the cylindrical. wall of the lower section 1 projects but slightly above the stool at the front of the furnace so that only a slight lifting of the crucible 6 is required to perinit it to pass out through the open front of the furnace.

By reason of the inclined oint between the upper and lower sections of the furnace the extent of angular movement of the swinging section 2 required to open the furnace for insertion or ren'ioval of a crucible. is materially lessened and the center of gravity of the upper section when in open position remains in front of the pivot 4. Means are provided for retaining the section 2 in elevated position and to this end one of the lugs 88 is provided with a recessed portion which terminates in a shoulder 47 which is engaged by a pawl 48 to hold the upper section in the position shown in Fig. 4 whilea crucible is being removed and another crucible inserted in the furnace. The pawl 48 is fixed to a horizontal shaft 49 which is journaled in the lugs 87 below the outer ends of the lugs 88 and the shaft 49 at one end thereof is provided with a shiftable counterweight 50 which is loose upon the shaft and provided with spaced outwardly extending lugs 51 which engage with a cross pin 52 carried by the shaft to retain the counterweight in two positions, in one of which the center of gravity of the counterweight is to the outer side of the shaft 49 and tends to move the pawl 48 toward engaging position with respect to the lug 38 and in the other of which the center of gravity of the counterweight is upon the inner side of the shaft 49 and tends to move the pawl 48 away from the lug 88. hen it is desired to open the furnace the counterweight 50 is shifted outwardly' so that it presses the pawl 48 against the lug 88. The cover is then opened and the section 2 lifted through an angle sulficient to permit the pawl 48 to swing behind the retaining shoulder 4'7 of the lug 38. The section 2 is then released and held in elevated position by the pawl 48. When it is desired to close the furnace the counter-' weight 50 is shifted back toward the furnace so that its weight tends to disengage the pawl 48. The section 2 is then lifted slightly to permit the pawl 48 to drop out of engagenient with the shoulder 47 whereupon the section 2 may be lowered into engagement with the section 1. The turning movement of the shaft 49 in an outward direction is limited by the engagement of the pawl 48 with the under edge of the lug 88 and the turning movement of the shaft 49 in an inward direction islimited by means of a tailpiece 53 which is integral with the pawl 48 and extends to the opposite side of the shaft 49, the tail piece 53 being curved upwardly to engage 'with the outer end portion of the lug 38. The turning movement of the shaft 49 is thus just sufiicient to permit the pawl 48 to move into and out of engagement with the retaining shoulder47 and the movement I of the counterweight 50 upon the shaft 49 is just sufficient to permit the counterweight to exert a turning force upon the shaft 49 in either direction to engage or release, the pawl.

If desired the retaining latch may be made automatic in operation as shown in Fig. 7 of the drawing. In this case the upper section is provided with a lug 54 which corresponds to the lug 88 in the modification above described except'thatthe lug v54 is provided with a recess 55 which is formed to provide a retaining Shoulder 56 at its forward end and there is an outwardly projecting tooth 57 at the rear end of the recess 55. The retaining pawl 58 is fixed to a horizontal shaft 59 similar to the shaft 49 above described and upon the outer end of the shaft there is a shiftable counterweight 60 which exactly the same as the counterweight50 above described. The. pawl 58 has rigidly connected therewith a rearwardly extending tailpiece 61 which is in the path of movement of the tooth 57 and the pawl 58 has formed on the upper side thereof adja cent the shaft 59 a shoulder 62 which is also in the path of movement of the tooth 57; When the section 2 is raised the tooth 57 of the lug 54 may engage with the tailpiece 61 and turn the shaft 59 rearwardly until the counterweight 60 moves past deadcenter and swings to its outermost position in which it acts to press the pawl 58 toward engaging position. Vfhen the section 2 reaches the position shown in Fig. 4 the pawl 58 drops behind the shoulder 56 and serves to retain the section in elevated position. When it is desired to lower the section 2 to operative position thesect-ion is lifted a short distance causing the tooth 5? to engage with the shoulder 62 on the pawl swinging the. pawl to disengaging position and rotating the shaft 59 sufficiently to cause the counterweight 60 to move past dead center and to swing inwardly to a position in which it acts to hold the pawl in disengaged position, The section 2 may then be lowered to opera tive position and during the downward movement thereof the tooth 57 o the lug l 54 moves outwardly and rides over the tailpiece 61 causing the shaft 59 to be turned in an outward direction to shift the counterweight 60 outwardly past dead center so that it acts to press the pawl 58 toward engaging position. If the counterweight should be accidently shifted inwardly during operation. of the. furnace the engagement of the tooth with the tail piece t'll. iiluring the raising of the movable section will shift the counterweight outwardly lo a position in which it acts to press the pawl 58 toward engaging position.

Having described my invention, 1 claim- 1. A crucible furnace comprising a casing having a fixed lower section adapted to support a. crucible, an upper section mounted for swinging movement about a horizontal axis and aoaptcd to rest upon the lower sec tion, a cover lllOViLlJl'y mounted on the upper section and adapted when in open position to counterbalance said upper section 2. A crucible turnace comprising a casing adapted to enclose a crucible, said ca. iug being divided into upper and lower sec-- tions, the meeting); edges of which are in cliued with respect to the horizontal, and means for pivotell supporting the upper section to swing vertically.

3. A crucible furnace comprising a casing adapted to cnclosea crucible, said c; sing" llfilllg' divided into upper and lower sections, the meeting edges ot which a re inclined with respect to the horizontal and a horizontal pivot connecting said sections adjacent the uppermost portion of the wall at the lower section.

4-. A crucible furnace comprising a casing adapted to encloie a crucible, said casing being divided into upper and lower sections, the meeting edges of which join in a plane inclined with respect to the horizontal, sealing means for forming a gas tight connec tion between the sections, and means for pivotall supporting the upper section to swing vertically.

5. A crucible furnace comprising a casing having a tired lower section having a base portion adapted to support a crucible and a tubular enclosing wall which is higher at one side of the casing than at the other, a tubularupner section formed to rest upon the upper edge of the wall of the lower section, and means adjacent the higher side of the wall of the lower section for pivotally supporting the upper section for swinging movement about a horizontal axis.

6. A crucible furnace comprising a casing having a fixed lower section having a base portion adapted to support a crucible and a tubular enclosing wall higher at one side than at the other. a tubular upper section ai'lapted to rest upon the upper edge of the wall of the lower section, means tor pivotah l v supporting said upper .ecl'iou l'or swinging movement about a horizontal axis, and means for counterlailancing said upper section.

7, A crucible turnace comprising a casing termed of upper and lower sections each having an outer metallic shell and a heat resisting lining, the meeting edge portions of the outer shell of said sections being pro vided one with a groove having a heat resistant packing ring therein and the other with a rib having a tapered edge engagcaliile with the packing ring, the said groove being in the upper section and the said rib being on the lower section.

8. A crucible furnace comprising a casing having a fixed lower section adapted to support a crucible, an upper section connected by a horizontal pivot to the lower section at one side thereof, and a cover having a piv otal connection to the upper section on the same side of thecasing as the first mentioned pivotal connection.

9. A crucible flurnace comprising a casing having a fixed lower section adapted to support a crucible, an upper section to rest upon the lower section, a horizontal pivot at one side of the casing connecting said sections, said upper position being movable upwardly about the pivot to a position peruiitting insertion or removal of a crucible from the lower section, and a laterally swinging cover connected by a vertical pivot to the uopcr section on the same side of the as the first mentioned pivot.

. A ClllCllUlC furnace comprising a caring having a tired lower section adapted to si' :ort a crucible, a vertically swinging upi" scctlon adapted to rest upon said lower section, outwardly extending lugs carried by said upper and lower sections, a horizontal pivot pin connecting said lugs, and a pawl cngageable with the lug ot' the upper section to retain the same in elevated position,

11. A crucible furnace comprising a casinghaving a fined lower section adapted to support a crucible, a vertically swinging upper section adapted to rest upon said lower section, means at one side of the casing for pivotally supporting said upper section, a pawl engageable with a part of the upper section to hold the same in elevated position, and means for engaging and disengaging said pawl.

12. A crucible furnace comprising a casing having a fixed lower section adapted to support a crucible, a vertically swinging upper section adapted to rest upon said lower section, means forming a fixed support for the upper section at one side of the casing, a horizontal pivot connecting the upper section to the supporting means, a horizontal shatt having a pawl thereon engageable with a part ot the upper section to retain the same in elevated position and a shiltablc counterweight carricd by said shaft.

13. A crucible furnace comprising a :asiug having a lower section adapted to sup port a crucible and an upper section adapted to rest upon the lower section, means for pivot-ally supporting the upper section to swing about a horizontal axis, a pawl adapt ed to engage a part carried by the upper section to retain the same in elevated position. a coui'iterweight connected with said pawl. and movable tron'i a pc ion in which it acts to press said pawl toward engaging position to a position in which it acts to press .said pawl away from engaging position and means for limiting the movement of said pawl.

14. A crucible furnace comprising a casing having a lower section adapted to sup port a crucible and an upper section adapted to rest upon the lower section, means for pivotally supporting the upper section to swing about a horizontal axis, and means for releasably retaining said upper section in raised position comprising a toothed member connected to the upper section, a pivoted pawl engageable with said member to retain the upper section in elevated position, a counterweight movably connected to said pawl and adapted to be shifted from one side to the other of the pivotal axis of the pawl to hold the pawl toward engaging position or to hold the pawl away from engaging position, and means controlled by movements of the upper section for shifting said counterweight.

15. A crucible furnace comprising a casing adapted to enclose a crucible, a jet burner adapted to project a flame into said casing, means for delivering fuel to said burner, said casing having hollow-bottom and side walls forming an air heating chamber, said chamber communicating with said burner, means for admitting air to said chamber, and drain passages extending through said hollow bottom wall.

16. A crucible furnace having a tubular body and a horizontally disposed laterally swinging cover adapted to rest upon the top edge of the body, said cover being connected to the bodyby a pivot pin which is disposed at a slight angle with respect to the vertical.

17. A crucible furnace comprising a casing adapted to enclose a crucible, said casing having hollow sine and bottom walls forming an air chamber extending around and across the bottom thereof, a jet burner having a nozzle extending through the side of the casing, means for delivering fuel to said burner, said burner having means for admitting air thereto from said air chamber, r

and an air supply pipe communicating with the hollow bottom at a point spaced circumferentially with respect to said nozzle whereby the air in passing to the nozzle flows across the bottom and around the sides of thecasing.

In testimony whereof, I hereunto affix my signature.

FRANKLIN M. ILER. 

